Foreground/background image segmentation is a process whereby regions in an image which depict foreground are separated from regions depicting background. Image segmentation can be thought of as a type of labeling process whereby image elements are labeled as depicting foreground or background, or as depicting objects of particular classes or categories.
Image segmentation is useful for many different purposes including image editing and to provide input to a downstream image processing facility. In the case of image editing, end users often desire to segment out a foreground region of an image in order to apply image processing to that foreground independently of the background region. For example, to adjust color balance of the foreground region, to carry out super-resolution on the foreground region, to add the foreground region to another image to form a composite image, to perform blurring on the background region to achieve an artificial depth of field, or for other purposes. The images themselves are digital still images, images which are part of a video, or other types of images including medical images, depth images, or others.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known image segmentation apparatus.